This study was conducted in pursuit of determining the level of technical assistance provided by the schools’ division office (SDO), lessons learned, and challenges in the full implementation of school-to-school partnership (STS). The study was descriptive in nature involving both qualitative and quantitative analyses. Purposive sampling was employed in identifying both leader and partner school-heads. This study used self-made instrument in which items were taken from the provisions reflected in the issuance under the STS partnership. The instrument was validated by the experts with the STS focal person. Findings revealed that both leader and partner school-heads rated very much evident as to the technical assistance provided by the SDO. There was no significant difference between the respondents’ perceptions on the level of technical assistance when grouped by type of recipient schools. Innovations were observed during the implementation of STS partnership such as mentoring, sharing of best practices, development and production of IMs, and conduct of LAC sessions. Additionally, there were lessons learned along the STS journey, namely, strengths and weaknesses identification, values of cooperation and teamwork, and sharing of knowledge and best practices. However, challenges were encountered such as limited time of implementation, distance of the leader school from the partner school, overlapping schedules, and inferiority of leader school to the partner school. STS promotes social trust, awareness, and understanding with other schools. Technical assistance from SDO plays a vital role in achieving success. It creates an avenue for the leader schools to share best practices and resources to their partner schools, thereby, creating an atmosphere of collaborative professional development strategies and activities. It is recommended that the identification of the leader schools could be division-based, not central-based considering that the division personnel knew better their context, especially on the characteristics of the low and high performing schools both access and quality.